This application is based on Japanese Patent Application No. 2002-260031 filed on Sep. 5, 2002, the disclosure of which is incorporated herein by reference.
The present invention relates to a right and left temperature independent control-type air conditioning unit that separately controls temperature of right and left regions of a passenger compartment. Particularly, the present invention relates to a fixing structure of a case of the air conditioning unit and a partition wall that divides an air passage in the case into a first air passage and a second air passage.
For example, JP-A-10-29420 discloses a right and left temperature independent control-type vehicular air conditioning unit. In the air conditioning unit, an air passage formed in an air conditioning case is divided into a driver side air passage and a passenger side air passage by a partition wall.
As a structure of fixing such partition wall to an air conditioning case, for example, examples shown in FIGS. 4A through 6 are proposed. According to the example shown in FIGS. 4A through 4D, a resinous air conditioning case has a right case 11a and a left case 11b. The right case 11a and the left case 11b are fixed to each other in a condition that a periphery of a resinous partition wall 12 is interposed between an engaging end surface 26a of the right case 11a and an engaging end surface 26b of the left case 11b. 
The right case 11a is formed with a step 40 on its engaging end surface 26a. The step 40 is recessed from the end of the case by a distance same as a thickness of the partition wall 12. As shown in FIG. 4A, first, the periphery of the partition wall 12 is placed on the step 40 as shown by an arrow K. Next, the engaging end surface 26b of the left case 11b is brought into contact with the engaging end surface 26a of the right case 11a, as shown by an arrow L. In this way, the periphery of the partition wall 12 is interposed and fixed between the engaging end surfaces 26a, 26b of the cases 11a, 11b. 
Further, a linear projection 29 is formed on the engaging end surface 26a to extend parallel to a longitudinal direction of the engaging end surface 26a, as shown in FIG. 4C. A linear groove 30 is formed on the engaging end surface 26b to extend parallel to a longitudinal direction of the engaging surface 26b, as shown in FIG. 4D. The linear projection 29 is fitted in the linear groove 30, so the cases 11a, 11b are sealed between the engaging end surfaces 26a, 26b. 
In a case that the cases 11a, 11b are used for a normal-type vehicular air conditioning unit, which does not have right and left temperature independent control function, the partition wall 12 is not required. Thus, the partition wall 12 is removed from the cases 11a, 11b. However, the periphery of the partition wall 12 generally has a complicated structure to correspond to a complicated form of the air passage in the air conditioning unit. Also, since the entire periphery of the partition wall 12 is interposed between the engaging end surfaces 26a, 26b, a total length of the periphery of the partition wall 12 increases.
In addition, since the cases 11a, 11b are resin molded articles, the precision of dimensions is generally lower than that of metallic articles. Therefore, it is difficult to closely fix the periphery of the partition wall 12 between the engaging end surfaces 26a, 26b at the same time as fitting the linear projection 29 into the linear groove 30. This results in an increase in the number of steps for assembling the air conditioning.
To address this matter, a structure shown in FIGS. 5A and 5B is proposed. The partition wall 12 is formed with a substantially T-shaped fixing portion 41 on its periphery. The fixing portion 41 has linear projections 29xe2x80x2 on the end surfaces. The fixing portion 41 is arranged between the engaging end surface 26a, 26b of the cases 11a, 11b so that the linear projections 29xe2x80x2 are fitted in linear grooves 30a, 30b formed on the engaging end surfaces 26a, 26b. Therefore, the partition wall 12 is fixed by interposing the T-shaped fixing portion 41 between the engaging end surfaces 26a, 26b. 
According to the example shown in FIG. 5A, the partition wall 12 is fixed merely by fitting the linear projections 29xe2x80x2 of the fixing portion 41 into the linear grooves 30a, 30b. Therefore, the partition wall 12 is easily fixed, and hence steps of the assembly is reduced, as compared with the structure shown in FIGS. 4a and 4B. However, in a case that the cases 11a, 11b are used for the normal-type air conditioning unit, a plate member 42 is required between the engaging end surfaces 26a, 26b, in place of the fixing portion 41 of the partition wall 12. Since the plate member 42 is additionally required, manufacturing costs increase.
According to another example shown in FIG. 6, the cases 11a, 11b are integrally provided with holding wall portions 43, 44 on the inside walls. The holding wall portions 43, 44 bend to have substantially L-shaped cross-sections. The partition wall 12 is fixed by interposing T-shaped fixing portion 41 in the L-shaped holding wall portions 43, 44. However, the shape of the cases 11a, 11b are complicated because of the L-shaped holding wall portions 43, 44. Thus, this increases the manufacturing costs.
The present invention is made in view of the foregoing matter and it is an object of the present invention to provide a simple fixing structure of a case of an air conditioning unit and a partition wall, which separates an air passage in the case into a first air passage for a right region of a passenger compartment and a second air passage for a left region of the passenger compartment.
According to the present invention, an air conditioning unit for a vehicle includes a case and a partition wall disposed in the case. The case defines an air passage through which air flows toward a passenger compartment of the vehicle. The partition wall is disposed so that it divides the air passage into a first air passage through which air flows toward a right region of the passenger compartment and a second air passage through which air flows toward a left region of the passenger compartment.
The case includes a first case for forming the first air passage and a second case for forming the second air passage. The first case and the second case are joined to each other by connecting a first case end surface of the first case and a second case end surface of the second case. Each of the first case and the second case has a plurality of pin contact portions. The partition wall is interposed between the pin contact portions of the first case and the pin contact portions of the second case.
Accordingly, since the partition wall is interposed between and fixed by the pin contact portions, the partition wall is easily fixed. Since the partition wall is not interposed between the first case end surface and the second case end surface, it is not necessary to closely contact the partition wall with the first case end surface and the second case end surface. Further, the first case and the second case are also used for a case of a normal-type air conditioning unit, which does not separately control temperature of the right region and the left region, by merely removing the partition wall.
Preferably, the pin contact portions are provided as portions that are knocked by ejector pins after an injection molding so that the cases are quickly removed from molding dies. Since the pin contact portions are used not only for the portions for receiving the ejector pin but also for the portions fixing the partition wall. Thus, it is not necessary to additionally form portions for fixing the partition wall.